module Music.Theory.Tempo_Marking where
import Music.Theory.Duration
import Music.Theory.Duration.RQ
import Music.Theory.Time_Signature
type Tempo_Marking = (Duration,Rational)
rq_to_seconds :: Tempo_Marking -> RQ -> Rational
rq_to_seconds (d,n) x =
let d' = duration_to_rq d
s = 60 / n
in (x * s) / d'
pulse_duration :: Time_Signature -> Tempo_Marking -> Rational
pulse_duration t (x,i) =
let j = recip (ts_duration_pulses t x)
s = 60 / i
in j * s
measure_duration :: Time_Signature -> Tempo_Marking -> Rational
measure_duration (n,d) t = pulse_duration (n,d) t * fromIntegral n
measure_duration_f :: Fractional c => Time_Signature -> Tempo_Marking -> c
measure_duration_f ts = fromRational . measure_duration ts